124 PHILOSOPHICAL TRANSACTIONS. [aNNO 1725. 



glass, narrowing downwards, and from I to 4 drops of the solution of vitriol, 

 more or less, as was found sufficient to produce the blue tincture; and care- 

 fully viewing it, he observed that the said French brandy had a pale blue tinc- 

 ture communicated to it, from the solution of Goslar, and that of Dautzic 

 vitriol; as also a bluish tincture from Hungary vitriol; from the solution of 

 the Cyprus vitriol it had not a blue but a greenish tincture ; from the solution 

 of English vitriol, and from that of vitriol of iron, prepared with oil of vitriol ; 

 and likewise, the solution of vitriol of iron, made by precipitation, a very ele- 

 gant tincture ; but it had the most beautiful of all, from the solution of Hessian 

 earth. The reason of this diversity of tinctures has been given above. 



VI. Further, for each probatory experiment he took also 4- oz. of malt spirits, 

 and put to them 1 , 2, 3, to 10 drops and upwards, of each solution of vitriol; 

 yet he could not observe the least bluish tincture produced. 



VII. Afterwards for each experiment he took x oz. of the adulterated French 

 brandy of N° III, and dropping into it, as also into common French brandy, 

 some of each of the solutions of vitriol of N° V, the experiments agreed in all 

 respects ; only that, on account of the combination of the extracts of the 

 various vegetables, there happened some, though a very inconsiderable, differ- 

 ence, as shall appear from what follows : 



VIII. The malt spirits became somewhat black, on dropping into them some 

 of the solution of Goslar and Dantzic vitriol, with an extract of galls ; and 

 with the solution of Hungary vitriol, at first a bluish tincture, but on mix- 

 ing, they entirely lost it; the solution of Cyprus vitriol strikes no tincture 

 at all ; they had an elegant blue tincture from the solution of English vitriol ; 

 and from that of iron, both ways prepared, they at first had a blue tincture, 

 but on mixing and stirring them with a quill, they got a violet tincture; in 

 fine, a single drop of the solution of the mineral earth of iron gave them a 

 beautiful h\ue tincture. 



IX. Malt spirits, impregnated with an extract of pomegranate rind, and 

 mixed with the solutions of vitriol in the order abovementioned, had little or 

 no blue tincture ; and in the four former trials they appeared almost in the 

 same manner, as the abovementioned malt spirits, impregnated with the extract 

 of galls ; and in the latter, they immediately appeared of a somewhat green 

 tincture, and presently after somewhat resembling ink. 



X. On the contrary, malt spirits, with an extract of oak, somewhat resemble 

 French brandy ; and with the solutions of pure martial vitriols, but especially 

 with that from Hessian earth, the most beautiful blue is produced. With the 

 first four solutions of vitriol the appearance was the same as in other counter- 

 feited malt spirits, nay, as in French brandy itself. 



